The present invention relates to a liquid crystal display device, and, more particularly, to a liquid crystal display device having an enlarged image display area.
Liquid crystal display devices are used in television sets, personal computers, and as displays for mobile terminals. An active matrix type of liquid crystal display device has transparent substrates disposed in opposition to each other with a liquid crystal interposed therebetween.
FIG. 20 is a diagram of the interconnection lines provided on and at the periphery of a transparent substrate of a typical liquid crystal display device of the type which is currently being manufactured. A liquid-crystal-side surface of one of the transparent substrates is provided with gate lines GW, which are disposed to extend in the x (lateral) direction and to be juxtaposed in the y (longitudinal) direction, and drain (source) lines DW, which are disposed to extend in the y direction and to be juxtaposed in the x direction.
The gate lines GW and the drain lines DW cross one another at right angles, and a switching element and a pixel electrode are formed in each area surrounded by adjacent ones of the gate lines GW and adjacent ones of the drain lines DW, thereby forming a so-called pixel. The switching element is turned on by a scanning signal supplied from the corresponding one of the gate lines GW, and the pixel electrode is supplied with a video signal from the corresponding one of the drain lines DW via the switching element. The areas that are defined by the gate lines GW and the drain lines DW constitute a pixel area AR.
Mobile terminals are being reduced more and more in size, whereas their image display areas are being enlarged more and more to realize better visibility of displayed information. For this reason, in a liquid crystal display device such as shown in FIG. 1, the proportion of the pixel area AR in the transparent substrate is increasing more and more, whereas the peripheral area surrounding the pixel area AR is decreasing more and more. In the typical liquid crystal display device, circuit chips for driving the liquid crystal (hereinafter referred to as drivers) and connecting lines are disposed in the peripheral area.
The gate lines GW and the drain lines DW are electrically connected to a gate driver and a drain driver via gate connecting lines GC and drain connecting lines DC, respectively. In a liquid crystal display device, if the display area is made larger, the distance between each of the gate connecting lines GC or the drain connecting lines DC becomes shorter because of the narrowing of the peripheral area, resulting in the problem of electrical shorting of the gate connecting lines GC or the drain connecting lines DC. In addition, if each of the gate connecting lines GC or the drain connecting lines DC is made thin, the problem of disconnection occurs.
Furthermore, as the peripheral area becomes narrower, an area in which the drivers are disposed becomes smaller. A gate driver GDr has gate signal output terminals on a long side closer to the pixel area AR. The gate connecting lines GC pass through a portion under the gate driver GDr and are connected to a gate common line GCOM. Accordingly, terminals for transmitting or receiving signals cannot be disposed on the side of the gate driver GDr that is closer to a short side of the panel PNL.